Prolonged Grief Disorder (PGD) is a psychiatric condition more severe and unremitting than normative grief, occurring in about 10% of bereavement. It is marked by prolonged yearning for the deceased, bitterness, interpersonal disengagement, and a sense of meaninglessness. PGD is associated with considerable functional impairment, physical and mental health morbidity, lost productivity, suicide, and lowered quality adjusted life years. At present, there are no evidence-based, secondary prevention interventions for PGD. The long-term goal of this research is to address the need for an efficacious, cost-effective, resource-efficient, and readily tolerated secondary prevention intervention for those at risk for developing PGD. The primary objective is to develop and pilot-test an internet-based self-management intervention for PGD that employs empirically derived cognitive-behavioral therapy (CBT) strategies to promote stable, active routines, self-care, accommodation of loss, enhanced self-efficacy, reengagement in pleasurable activities, and reattachment with significant others. The proposed work capitalizes on established CBT techniques and recent research on using the internet to deliver CBT interventions, and is intended to provide the necessary development and pilot work for a large clinical trial. The key hypothesis is that this intervention will reduce PGD symptoms and associated functional impairments. We hypothesize that participation in the intervention will be high due to the increased anonymity and accessibility afforded by the internet, which reduces stigmatization, increases treatment compliance, and, in turn, will increase treatment response. We will accomplish the objectives by pursuing these specific aims: (1) Search the loss and PGD literature and collaborate with experts to develop an experiential and skills-based, 6- week, therapist-assisted self-management protocol;(2) Develop a tool to assess the maladaptive cognitions and perceived barriers that may prevent PGD patients engaging in effective self-care, and reengaging their social circle (and implement the tool in the intervention);(3) Develop and refine an interactive, easy-to-negotiate internet interface with underlying data capture and treatment monitoring capabilities to implement the protocol;(4) Validate and standardize the treatment protocol and internet interface based on feedback from experts, care providers, and patients;(5) Conduct a pilot trial to determine feasibility, safety, efficacy of the intervention, the usefulness of the internet treatment delivery and monitoring technology, and further refine the intervention based on feedback from participants who complete the protocol.